Abrasive wheel



Jan. 29, 1935. G. H. ABULLARD 1,989,074

A BRAsIvE WHEEL Filed July 2s, 1951 lfm George H. 511,2 l afd ,f w MMMPatented Jan. 29, 1935 UNITED STATES PATENT ,ol-FICE 1,989,074 yABRASIVE WHEEL George H. Bullard, Westboro, Mass. Application July 23,1931, Serial No. 552,577

10 Claims.

y 'I'he present invention relates to abrasive wheels and particularly tothin large-diameter abrasive 'Wheels commonly known as coping,

wheels, for use in sawing stone or similar material.

Abrasive wheels of this type are usually in the form of a.thin metalliccentral hub or disk with a relatively narrow annulus of abrasivematerial molded thereon to imbed the outer periphery of the disk. Such awheel in actual use has a relatively short life, owing to the denitelimitation placed on the radial width of the abrasive marginal portion,by the extreme thinnessA thereof; heretofore, all attempts to increasethe radial width of the abrasive (to give longer life to such a wheel)have resulted in failure, because of the tendency of the abrasive to nyapart as a result of centrifugal force or to break oif under thepressure exerted by the wheel against the material being cut.

According to the present invention, a lreinforcing -means is imbedded inthe annulus of abrasive material, said reinforcing means being attachedto and extending outwardly from the rim of the central metallic hub ordisk. This provides not only a reinforcement against breaking as aresult of the high speeds but also reinforcing the material againstcrushing. The reinforcing material is such that it wears away at leastas fast as the abrasive material is worn away. By this reinforcement, itis possible greatly to increase the length of life of abrasive wheels ofthis character since a much greater radial width of abrasive materialmay be built up than in previous constructions. Other and furtherobjects and advantages of the invention will appear with reference tothe accompanying drawing in which:-

Fig. 1 is a plan view of an abrasive wheel, parts thereof being brokenaway, more clearly to show the invention.

Fig. 2 is a section along the line 2-2 of Fig. 1.

Fig. 3 is a fragmentary plan view partly in section showing amodification.

Fig. 4 is a fragmentary plan view partly in section showing anothermodification.

Fig. 5 is a section along the line 5 5 of Fig. 4.

Like reference characters refer to like parts throughout the drawing.

Referring to the drawing and particularly to Figs. 1 and 2, the abrasivewheel includes a relatively thin hub or disk 1 having an opening. 2centrally thereof for the reception of a shaft'on which the abrasivewheel is to be mounted. The material of the disk 1, near-its rim, is cutaway by a series of substantially circular openings that' intersect theouter periphery 4 thereof, forming` in effect a series of dovetailcut-outs or recesses 3, 3, each having a relatively narrow throat oropening at the disks periphery.

The thin ring or annulus 5 of abrasive material which is molded to imbedthe rim of disk l and to interlock with Ithe dovetails or cut-outs 3, 3.also imbeds, as shown in Fig. 1, a plurality of reinforcing members 6,6, each of the latter, previous to the molding operation, having beenoperatively associated with one of the dovetail cutouts 3 of the centraldisk. Each reinforcement 6 comprises a wire or the like bent intosubstantially U-shaped form, with the base 7 of the bend so shaped as tot with and conform to the substantially circular contour of each of theassociated dovetail cut-outs- 3 of disk 1. That is to say, eachreinforcement 6 has its base 7 interlocked with one of the rim recesses3, and the two sides or legs of said reinforcement, beyond the narrowthroat of said recess 3, are preferably divergent, so as to increase theresistance to fracture or breakage of the abrasive ring 5 that embedsthe entire series of reinforcements.

In the embodiment shown in Fig. 3, the central disk 1 is constructed inthe same manner as in Fig. 1, and the reinforcing member in thismodication consists of a thin plate in the formof a ring 8 having alarge number of perforations 9 therein. The inner edge of the ring whichis substantially equal in diameter to the diameter of the disk isprovided with protruding portions 10 substantially matching the cut-outportions 3' in the disk, said protruding portions being arranged toengage and interlock with the cut-out portions to maintain theperforated plate in position. By reason of the large number ofperforations, into which the abrasive material from opposite sides ofthe plateextends, a substantially soid abrasive ring is provided and thematerial is firmly interlocked with the reinforcing member on oppositesides thereof. The plate acts in the same way as the reinforcing membersshown in Figs. 1 and 2 to support the abrasive material against crushingor iiying apart, the material being such that the plate wears away atleast as rapidly as the abrasive material. y

In the construction shown in Figs. 4 and 5, the central hub or disk 12is provided at its periphery 13 with thin radially extending ngers 14substantially in the plane of said disk, which fingers v14 may be eitherintegral with the disk or may be separately formed vand permanentlysecured to said disk to form a functionally integral part thereof. Thesengers form radially extending reinforcements which are imbedded in theannulus 15 of abrasive said annulus lagainst breaking, said annulusbeing similar in construction to that shown in Figs. 1 and 3. Theabrasive material extends between the radially extending ngers andoverlies the disk adjacent the periphery, whereby said annulus ispositively secured to the disk to provide a substantially continuousannulus of abrasive material tosupport material extending beyond saiddisk in the plane thereof. Since the material from which the fingersareformed is such that, when the wheel is in use, the fingers are wornaway at least as rapidly as the abrasive material is worn away, asubstantially continuous grinding surface is provided on the outerperiphery of said annulus, until the abrasive material constituting saidannulus is worn away substantially to the po' t where the fingersconnect to the disk or hub. In this construction, as in the othermodifications, the reinforcing members embedded and extending throughthe annulus support said abrasive material against breaking undercentrifugal force or under crushing forces so that the radial width ofthe grinding portion of the wheel may be materially increased.

The dot-dash line 11 of Fig. 1 indicates generally the maximum radialwidth to which abrasive on the central disk with- That is to say,

material can be built up out the use of reinforcements.

when there is no reinforcement of the abrasive material beyond the rimofthe disk l, such material cannot safely be extended beyond thecircumference indicated at 11, because the bonding substance whichunites the abrasive particles is not strong enough to withstand thegreatly in.- `creased centrifugal force which becomes effective with anyincrease in diameter of the wheel. Consequently, it is not possible tomake the wheel much larger than the disk 1, except by providingreinforcements which aid in supporting the abrasive material againstflying apart by centrifugal force or crushing under the pressure betweenthe wheel and work. Especially in coping wheels, used for cutting stone,the reinforcing metallic members will wear away at least as rapidly asthe abrasive material and by the use of reinforcing members in themanner shown in the drawing, the effective diameter of the coping wheelcan be substantially increased, thereby providing'a wheel which can cutfora much greater time before replacement is necessary.

I claim,

. 1. An abrasive wheel comprising a central hub having cut-out portionsin its periphery, the openings to said portions being narrower than theremainder of said portions, an annulus of abrasive material extendingbeyond the hub and in substantially the same plane, and reinforcingmeans interlocking with said cut-out portion of said hub and imbedded insaid annulus.`

2. An abrasive wheel comprising a central metallic disk, an outer.annulus of abrasive material, said disk being provided with cut-outportions adjacent the periphery into which the abrasive material extendsto maintainthe abrasive material in place, and a reinforcing memberadapted to be embedded in the annulus, portions of said reinforcingmember engaging and interlocking with the cut-out portions.

l position,

3. An abrasive wheel comprising a central metallic disk and an outerannulus of abrasive material, said disk having cut-out portions adjacentthe periphery into which the abrasive material extends to retain theabrasive material in the openings from the periphery to said cutoutportions being narrower than the remainder of the cut-out portions and areinforcing member adapted to be embedded in thev annulus, portions ofthe reinforcing member engaging and interlocking with the cut-outportions.

4. In an abrasive wheel, the combination with a metallic supporting diskhaving a series of cut-out tending into the openings portions adjacentthe periphery thereof and an annulus of abrasive material secured to theperiphery of the disk and extending outwardly therefrom, of areinforcing member embedded in the abrasive material, portions'of saidmember engaging and interlocking with the cut-out portions.

5. An abrasive ,heel comprising a central metallic disk, the outer edgeof which is provided with recesses having narrow openings, an outer ringof abrasive material extending beyond the edges of the disk, portions ofthe abrasive material extending into the recesses to retain the materialin connection with -the disk, and reinforcing elements embedded in theabrasive material having portions extending into and interlocking withthe recesses to prevent radial withdrawal movement therefrom, saidreinforcing elements extending substantially to the outer edge ofthering of abrasive material.

6. An abrasive wheel comprising a central metallic disk, the outer edgeof which is provided with recessesy having narrow openings, an outerring of abrasive material extending beyond the outer edge of plane ofthe disk, portions of the abrasive material extending into the recessesto retain the material in position on the disk, and reinforcing elementsembedded in the abrasive material having portions extending into andinterlocking with the recesses to prevent radial withdrawal movementtherefrom, said reinforcing elements extending substantially to theouter edge of the ring of abrasive material.

'1. An abrasive wheel comprising a central metallic disk, the outer edgeof which is provided with recesses having narrow openings, an outer ringof abrasive material extending beyond the edges of the disk, portions ofthe abrasive material extending into the recesses to retain the recesseson the disk, and a reinforcing element comprising a perforated plateembedded in the ring, said plate having portions thereof engaging in therecesses of the disk.

8. An abrasive wheel comprising a central me- 4" tallic disk, the outeredge of which is provided with substantially circular openings, an outerring of abrasive material extending beyond the edges of the disk and insubstantially the plane of the disk, portions of the abrasive materialexto maintain the abrasive material in position on the disk and areinforcing plate embedded in the ring, portions of the plate engagingin the openings in the disk.

9. An abrasive wheel of the class described, comprising a centralsupporting disk, a continuous annulus of abrasive material imbedding therim of said disk and providing a cutting portion of substantial radialwidth 'beyond said rim, and reinforcing means imbedded in and adapted tobe worn down progressively with said cutting portion, said reinforcingmeans being secured to said rim.

10. An abrasive wheel of the class described, comprising a centralsupporting disk, a continuous annulus of abrasive material imbedding therim of said disk and providing a cuttingportion of substantial radialwidth beyond said rim, and a series of pairs of divergent reinforcingelements imbedded in and adapted to be worn down progressively with saidcutting portion, each pair being interlocked with said rim.

GEORGE H. BULLARD.

the disk, and in substantially thel

